1. Field of the Invention
The present invention relates to a disk array device and a remote copying control method for a disk array device.
In a disk array device, for example, numerous disk drives are disposed in the form of an array, so that the device is constructed on the basis of a RAID (redundant array of independent inexpensive disks). Logical volumes which are logical memory regions are formed in the physical memory regions of the respective disk drives. LUNs (logical unit numbers) are assigned to these logical volumes beforehand, the host computer can issue write commands or read commands of a specified format to the disk array device by specifying the LUN or the like. As a result, the host computer can read or write desired data from or into the disk array device.
A plurality of host computers can be connected to the disk array device. Here, in cases where data groups managed by a certain host computer or application program can be read from or written into other host computers or application programs, problems may arise. Accordingly, techniques such as zoning, LUN masking and the like are used. Zoning is a technique in which one or a plurality of zones are set in the disk array device, and the transfer of data is permitted only to specified communications ports or WWNs (world wide names) belonging to the zones. LUN masking is a technique in which specified host computers are allowed access to specified LUNs (Japanese Patent Application Laid-Open No. 2003-30053). Furthermore, in regard to remote copying, the conventional techniques described below are known (Japanese Patent Application Laid-Open No. 2002-334049 and Japanese Patent Application Laid-Open No. 2003-032290).
Limitations on the access of host computers to the disk array device can be set by conventional zoning or LUN masking. However, in the case of conventional techniques, only the limitation of access is possible; the exclusive use of resources or divisions of resources with security taken into account is impossible. Specifically, even in cases where access limitations are set, if instructions for an erroneous change in construction are issued from the storage management software of a managing terminal, this may possibly have an effect on resources used by other host computers.
Especially in cases where memory regions of the disk array device are assigned to a plurality of enterprises or the like and used by these enterprises or the like, it is necessary to set security so that the construction of the regions managed by the respective enterprises cannot by altered by the managing terminals used by other enterprises. In conventional techniques, however, no consideration is given to security in such cases.
In a disk array device, data backup is appropriately performed for purposes of data preservation and the like. So-called remote copying (or mirroring) is known as one such backup technique. In remote copying, data that is managed by a local system (this is a local disk array system, and may also be called a master system or primary system) is transferred to a remote system (remote disk array system) installed in location that is physically separated from the local system. As a result, data groups of the same content are respectively stored by the local system and the remote system.
Similarly, in cases where the memory resources of one disk array device are assigned to a plurality of enterprises or the like and are respectively used by these enterprises or the like, remote copying can be respectively performed for each of the use regions of the respective enterprises. Here, in cases where the local system and remote system are connected by (for example) an expensive dedicated line or the like, the band of the communications network that is used for remote copying is naturally limited. Accordingly, in cases where a plurality of different remote copying operations are performed using limited shared communications resources, the remote copying of the use region of a certain enterprise or the like may affect the remote copying of regions used by other enterprises or the like. Specifically, for example, if a certain remote copying operation occupies the entire band of the communications network for a long period of time, other remote copying operations cannot be performed while this remote copying is being performed, so that the there is a drop in the convenience of use and the like.
Accordingly, in the conventional technique described in Japanese Patent Application Laid-Open No. 2002-334049, all of the side files for which remote copying is performed are managed in the disk array device, and the quantities of data of the respective host computers that occupy the side files are individually controlled. Furthermore, in the conventional technique described in Patent Reference 3, the local system and remote system are connected via a channel extender, and a communications network is automatically selected from a plurality of communications networks on the basis of user policy.
However, even in cases where all of the side files are controlled within the disk array device, data transfer is accomplished via a limited shared communications network between the local system and the remote system. In the technique described in Patent Reference 2, since remote copying is performed by the shared use of limited communications resources between the local system and remote system, the respective host computers or application programs still affect each other, so that there is room for improvement.
Use bands can be assigned to respective communications ports using a channel extender as in the technique described in Japanese Patent Application Laid-Open No. 2003-032290. In this case, however, the communications ports must be assigned to the respective host computers beforehand, and in cases where the construction inside the disk array device is altered, the setting of the digital extender must also be altered accordingly. Consequently, in the case of the conventional techniques described in the abovementioned patents, alterations in the construction of the disk array device cannot be handled in a flexible manner, so that there is room for improvement in terms of convenience of use.